1. Field of the Invention
The present invention relates to fitness equipment, especially to a treadmill.
2. Description of the Prior Arts
A treadmill is commonly used fitness equipment which usually comprises a base frame, a treadmill belt, a plurality of bearing wheels, and a bearing frame. The treadmill belt is looped around and is mounted on the base frame, and is divided into an upper section, a lower section, and two end sections. The bearing wheels are mounted on an inner surface of the treadmill belt. The bearing frames are mounted on the base frame and support the bearing wheels on the upper section of the treadmill belt. In this way, the user can walk or run on the upper section of the treadmill belt to achieve the effect of exercise.
However, in a conventional treadmill, the bearing wheels are usually disposed vertically. In other words, an axle of the bearing wheel is horizontal, so that the bearing wheel can withstand larger force. However, the vertically disposed bearing wheel cannot withstand a lateral force. When the user walks or runs, it will inevitably cause a lateral force to the treadmill belt, such that the lateral force easily causes the treadmill belt to deviate in direction.
Some treadmills further provide a limiting member to abut and limit sidewalls of the bearing wheels and the treadmill belt, which may increase the resistance of the treadmill belt when the treadmill belt rotates, thereby making it difficult for the treadmill belt to maintain a constant rotation resistance. The limiting member also generates friction with the sidewalls of the bearing wheels or the sidewall of the treadmill belt, which is prone to wear and noise easily. Moreover, when the friction is too large, the treadmill belt may be stuck and result in a sudden stop, which may cause the user to fall down and is a certain safety risk.